Display screen or portion thereof with an icon



FIG. 1 is a front view of a first embodiment of a display screen orportion thereof with an icon showing my new design; and,

FIG. 2 is a front view of another embodiment of a display screen orportion thereof with an icon showing my new design.

The broken lines represent the display screen and form no part of theclaimed design.

CLAIM The ornamental design for a display screen or portion thereof withan icon, as shown and described.